<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style type="text/css">
      .box {
        margin: 0 auto;
      }
      a {
        width: 100px;
        background-color: #ef82a0;
        /* a标签默认为行级标签, 需改为行内块标签*/
        display: inline-block;
        text-align: center;
        line-height: 3;

        /* 去除文字轮廓 */
        outline: none;

        /* 去除下划线 */
        text-decoration: none;
      }

      a:active {
        background-color: #bb6a81;
      }
    </style>
  </head>
  <body>
    <div class="box">
      <a href="#">Link One</a>
    </div>
  </body>
</html>
